JPH0946117A - Antenna system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an antenna system inexpensively with less number of components in which only a rod antenna element and a helical antenna element connected in series act like an antenna section while the rod antenna element contained retractively in the case of a portable radio equipment is extracted and only the helical antenna element acts like the antenna section while the rod antenna element is contained in the case. SOLUTION: A rod antenna element 4 and a helical antenna element 2 are made of a continuous metallic wire material and a feeder metallic fixture 7 is made up of a leaf spring 8 clipping the metallic wire elastically, then components such as a connection metallic fixture or the like to connect the rod antenna element 4 and the helical antenna element 2 are not required. Furthermore, the helical antenna element 2 is covered by a mold cap 3 integrally, then the man-hours required to mount the mold cap 3 is omitted.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device provided in a portable wireless device such as a mobile phone, and more particularly to an antenna device in which an antenna portion is attached to a housing of the portable wireless device so as to be retractable.

[0002]

2. Description of the Related Art In a portable wireless device such as a mobile phone which is used while being carried, an antenna portion protruding from the housing of the portable wireless device is used to make the antenna as compact as possible while moving. It can be retracted so that it can be stored inside.

However, in this type of portable radio device, transmission / reception cannot be sufficiently performed with the antenna part housed in the housing, and in particular, the reception sensitivity of the calling signal deteriorates, so reception is awaited. I had to pull out the antenna while I was.

In order to solve this drawback, Japanese Patent Laid-Open No.
As shown in No. 245603, even when the rod antenna element is housed in the housing,
Antenna devices capable of transmitting and receiving have been developed.

This conventional antenna device is shown in FIGS.
0 will be described.

As shown in FIG. 6, a ring-shaped power supply fitting 102 is attached to the upper surface of the housing 101 of the portable wireless device 110, and the power supply fitting 102 is inserted through an insertion hole.
The rod antenna element 103 of the antenna device can be projected and retracted in the housing 101.

Then, as shown in FIG. 7, a substantially helical helical antenna element 104 is continuously provided at the tip of the rod antenna element 103, and the rod antenna element 103 and the helical antenna element 104 each have a length of ¼ wavelength. Since it has a housing 101
When the rod antenna element 103 is extracted from the antenna, the antenna has a length of ½ wavelength.

In this state, the rod antenna element 10
The lower end of 3 is in electrical contact with the power supply fitting 102, and the power supply fitting 1
Further, 02 is connected to a transmission / reception circuit (not shown) on the circuit board 106 via the power supply line 105.

When the rod antenna element 103 is housed in the housing 101, as shown in FIG.
The upper end of the rod antenna element 103 is the power supply fitting 10.
The helical antenna element 104, which is in contact with the antenna 2 and protrudes from the housing 101, acts as a quarter wavelength antenna. At this time, the rod antenna element 10
The lower end of 3 is brought into contact with the ground piece 106a, and the power supply fitting 10
The impedance viewed from 2 is set to infinity so that the rod antenna element 103 does not function as an antenna.

Therefore, even in this state in which the rod antenna element is housed, the portable radio device 110 can perform transmission / reception.

The rod antenna element 103 maintains the pulled out state and the housed state by:
The contact with the power supply fitting 102 must be made elastic to some extent. In addition, the helical antenna element 10
No. 4 needs to be covered with a cap so that the substantially spiral parts do not come into contact with each other and short-circuit due to contact with the outside. Therefore, the antenna portion including the rod antenna element 103 and the helical antenna element 104 has a structure as shown in FIG.

That is, in the figure, the rod antenna element 103 has an antenna core material 107 covered with a tube 108 of polyacetal or the like. Further, tubular metal fittings 109 and 111 are provided around the tube 108 at upper and lower ends slightly exposed from the tube 108, and are in electrical contact with the antenna core material 107.
Thereby, the elasticity of the tube 108 is used to make the metal fitting 1
09 and 111 can elastically contact the ring-shaped power supply fitting 102.

Further, the helical antenna element 104
Is a resin cap body 112 and a cap upper lid 1
The entire circumference is covered with 13. Cap body 112
The lower end of the helical antenna element 104 is led out to the bottom of the, and is electrically connected to the conducting metal fitting 114. The conductive metal fitting 114 is continuous with the metal fitting 109 by crimping.

[0014]

However, according to the above conventional technique, the number of parts is increased. That is, as described above, in addition to the antenna core material 107, the tube 108 and the metal fitting 10 are provided to ensure elastic contact.
9 and 111 are required, and the rod antenna element 10
In order to connect the 3 and the helical antenna element 104 continuously, the conductive metal fitting 114 and the metal fitting 109 are required,
The cap body 112 and the cap upper lid 113 are required to prevent the helical antenna element 104 from being short-circuited.

Further, since the number of parts is increased, the cost of the entire apparatus becomes expensive.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an antenna device which requires a small number of parts and which can reduce the cost of the device.

[0017]

In order to solve the above problems, an antenna device according to a first aspect of the present invention is a rod-shaped rod antenna element in which a substantially helical helical antenna element is continuously provided at the tip of the rod antenna element. The element is stored in the housing of the portable wireless device so that it can be retracted and retracted, and the lower end of the rod antenna element comes into contact with the power supply metal fitting when it is pulled out from the housing, and both elements function as the antenna part and are housed in the housing. In the antenna device in which the upper end of the rod antenna element comes into contact with the feeding metal fitting and only the helical antenna element functions as an antenna, the rod antenna element and the helical antenna element are formed of one continuous metal wire rod, and the power feeding metal fitting is a metal wire rod. Characterized by being constituted by a leaf spring that elastically clamps

The antenna device according to a second aspect of the present invention is further characterized in that the helical antenna element is covered by a mold cap integrally molded.

[0019]

In the antenna device according to the first aspect of the present invention, the rod antenna element and the helical antenna element are formed of a single metal wire and are continuous as a unit. Further, the power supply fitting made of a leaf spring elastically clamps and electrically connects the rod antenna element made of a metal wire.

Further, in the antenna device according to the second aspect, the helical antenna element is covered with the integrally molded mold cap, and it is not necessary to separately assemble the cap main body 112 and the cap upper lid 113.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 3, in the antenna device according to the present embodiment, when the portable wireless device 1 is moved, the mold cap 3 integrally formed with the helical antenna element 2 (see FIG. 1) is left. The rod antenna element 4 is stored in the housing 5 of the portable wireless device 1.

When performing normal communication from this housed state, the mold cap 3 is pulled up and the rod antenna element 4 is pulled out from the housing 5 as shown in FIG.

Hereinafter, each part will be described in detail.

The rod-shaped rod antenna element 4 and the spiral-shaped helical antenna element 2 are continuously formed from the beginning by a continuous piano wire which is a single metal wire rod. The helical antenna element 2 is formed by spirally winding a piano wire in order to reduce the protruding length, and is used as an antenna having a quarter wavelength of a radio signal for transmission and reception. For example, when the portable wireless device 5 is a mobile phone such as a car phone, the operating frequency is in the 800 to 900 MHz band, so a piano wire with a developed length of about 14 cm is used, and a diameter of 0.5 cm and a height of 2 The helical antenna element 2 has a centimeter spiral shape.

The portion of the rod antenna element 4 is a linear piano wire having a length of ¼ wavelength of a radio signal to be transmitted and received. That is, in the above example, 8
Use a straight piano wire with a length of ~ 9 cm. Therefore, a total of 22 to 23 cm of piano wire is used.

The portion of the helical antenna element 2 is covered with a mold cap 3 which is integrally molded. The portion of the mold cap 3 through which the piano wire penetrates is firmly bonded to the integrally molded resin material, and no metal fitting or the like is required for bonding. Further, a groove 6 is formed on the outer periphery of the mold cap 3, and the mold cap 3 is pinched to facilitate pulling up the rod antenna element 4.

The rod antenna element 4 penetrates a hole 5b formed in a resin lid 5a provided in the housing 5. The lid portion 5a is fixed to the housing 5 with an adhesive, for example, when assembled.

The power supply fitting 7 that contacts the rod antenna element 4 is composed of a leaf spring 8 that elastically holds a piano wire. The power supply fitting 7 has a shape in which a single leaf spring 8 is folded back, and a piano wire is sandwiched between and supported.

The folded-back portion 9 having a folded shape has a large gap 9a so that the folded-back portion 9 is folded back with a large curvature so that the strength of the leaf spring 8 is not adversely affected. A pair of screw holes 12 are formed in both end portions 11 of the leaf spring 8, and are closed by screws 13. The gap 11a between both end portions 11 of the leaf spring 8 is largely open so that the screw 13 can be tightened smoothly when closing.

As shown in FIG. 2, the portion of the leaf spring 8 that sandwiches the piano wire, that is, the portion 14 between the folded-back portion 9 and both end portions 11 has a small gap 14a and is a crescent-shaped gap. By making the gap 14a small, a thin piano wire can be held. Further, the piano wire is positioned in the center of the crescent shape by forming the positioning groove 14b in the center of the crescent shape.

In order to attach the power supply fitting, a flange 15 (see FIG. 3) is formed inside the housing 5, and a hole through which the screw 13 that has been tightened is passed is formed. The tip of the screw 13 penetrating this hole is stopped by a nut 17, for example.

The power supply fitting 13 is connected to the antenna coupling circuit of the circuit board 19 by a power supply line 18 whose one end is sandwiched between the nut 17 and the flange 15. The circuit board 19 is a circuit board on which high-frequency circuit components (not shown) that form a transmitter circuit, a receiver circuit, an antenna coupling circuit, and the like of the portable wireless device are mounted.

At the lower end of the rod antenna element 4,
In order to prevent the power supply fitting 7 from falling off when pulled out (see FIG. 4), the retaining cap 21
Are insert-molded. The retaining cap 21 has a spindle shape so that the retaining cap 21 can be smoothly contacted with the ground 22 and can easily get over the ground 22.

This ground 22 contacts the rod antenna element 4 to make the impedance of the rod antenna element 4 viewed from the power supply fitting 7 infinite,
The rod antenna element 4 does not function as an antenna.

According to the above embodiment, the rod antenna element 4 and the helical antenna element 2 are formed by a piano wire which is a single metal wire and are continuous from the beginning. Therefore, a plurality of metal fittings 109 and 114 (see FIG. 10) are not required to connect both elements 103 and 104, which are separate from each other as in the conventional art, in series.

Further, since the power supply fitting 7 constituted by the leaf spring 8 elastically clamps and contacts the rod antenna element 4 formed of a metal wire, in order to secure the elastic contact as in the conventional case. , It is not necessary to give elasticity to the antenna part side. That is, as in the conventional case, in addition to the antenna core material 107, the tube 108 and the plurality of metal fittings 109, 1
11 (see FIG. 10) is not necessary and only one piano wire is required. Therefore, the number of parts can be reduced.

Further, the helical antenna element 2 is supplied by being covered with a mold cap 3 which is integrally molded. Therefore, unlike the prior art, the two parts of the cap body 112 and the cap upper lid 113 (see FIG. 10) are not required, and the assembly is also unnecessary. Therefore, the number of parts can be reduced.

Since the number of parts can be reduced in this way, the whole assembling work is easy and the cost of the apparatus can be suppressed.

Further, since the rod antenna element 4 is held in a wide portion by the power supply fitting 7, it is stable and stable.

Further, since both the elements 2 and 4 use the metal wire rod as it is, the amount of the rod antenna element 4 drawn out is larger than that in the conventional case where the antenna core 107 is covered with the tube 108. In spite of this, the power supply fitting 7 can always be electrically contacted and therefore always communicated.

The present invention is not limited to the above embodiment, but can be variously modified.

For example, in the above embodiment, the power supply fitting 7 was connected to the antenna coupling circuit of the circuit board 19 via the power supply line 18, but in other embodiments, one of the screws 13 is connected to the power supply line 1.
Instead of 8, the screw 13 may be directly soldered to the antenna coupling circuit for electrical connection (see FIG. 5).

Further, in the above embodiment, the helical antenna element 2 and the rod antenna element 4 each have a length of 1/4 wavelength, and the rod antenna element 4 is a 1/2 wavelength antenna when it is pulled out. In the embodiment, for example, the rod antenna element 4 may be a 3/8 wavelength antenna, and the rod antenna element 4 may be a 5/8 wavelength antenna in a pulled-out state.

Further, in the above-described embodiment, the retaining cap 21 is insert-molded at the lower end of the rod antenna element 4, but in other embodiments, the lower end of the rod antenna element 4 is bent like a hook to prevent retaining. Is also good.

In the above embodiment, in order to prevent the rod antenna element 4 from functioning as an antenna when the rod antenna element 4 is housed,
The rod antenna element 4 is grounded and the impedance of the rod antenna element 4 is infinite. However, in another embodiment, the influence of the high frequency signal radiated from the rod antenna element 4 can be eliminated by shielding the portion of the rod antenna element 4 housed therein.

In the above embodiment, the metal wire is a piano wire, but in other embodiments, other metal may be used. For example, an alloy of titanium and nickel in which the content of titanium is considerably reduced.

Further, in the above embodiment, the flange 15 is formed inside the housing 5 for attaching the power supply fitting 7, but in other embodiments, the flange 15 may be formed in the lid portion 5a.

In the above embodiment, the power supply fitting 7 is formed by folding back the leaf spring 8. However, in another embodiment, one leaf spring that is not folded back is attached to another member by a screw. A metal wire rod may be held between the other member and the leaf spring.

[0050]

According to the first aspect of the present invention, the rod antenna element and the helical antenna element are formed of a single metal wire and are continuous from the beginning. There is no need for a plurality of metal fittings in order to make the continuous.

Further, since the power supply fitting constituted by the leaf spring elastically clamps and contacts the rod antenna element formed by the metal wire, the antenna core material is secured in order to secure the elastic contact as in the conventional case. Besides, it does not require a tube or multiple fittings. Therefore, the number of parts can be reduced.

According to the second aspect of the present invention, the helical antenna element is further covered with the integrally molded mold cap, which does not require the two parts of the cap body 112 and the cap upper lid 113 as in the conventional case. Therefore, the number of parts can be reduced.

Since the number of parts can be reduced in this way, the cost of the device can be suppressed.

[0054]

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a main part of an antenna device according to an embodiment of the present invention.

FIG. 2 is a horizontal cross-sectional view of a main part of the antenna device according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view of essential parts showing a state in which the antenna of the antenna device according to the embodiment of the present invention is housed.

FIG. 4 is a cross-sectional view of essential parts showing a state where the antenna of the antenna device in FIG. 3 is pulled out.

FIG. 5 is a cross-sectional view of essential parts showing a state in which an antenna of an antenna device according to another embodiment of the present invention is housed.

FIG. 6 is an overall perspective view of a portable wireless device including a conventional antenna device.

FIG. 7 is a cross-sectional view showing a state in which an antenna of a conventional antenna device is pulled out.

8 is a cross-sectional view showing a state where the antenna of the antenna device of FIG. 7 is housed.

9 is a schematic diagram showing a state in which the rod antenna element is grounded in the housed state of FIG. 7. FIG.

FIG. 10 is a vertical cross-sectional view of an antenna of a conventional antenna device.

[Explanation of symbols]

 1 Portable Radio 2 Helical Antenna Element 3 Mold Cap 4 Rod Antenna Element 5 Housing 7 Power Supply Metal 8 Leaf Spring

Claims (2)

[Claims] 1. A rod-shaped rod antenna element (4) is continuously provided with a substantially helical helical antenna element (2) at a tip thereof, and the rod antenna element (4) is a casing (5) of a portable radio device (1). ) Is stored so that it can appear and disappear,
When the rod antenna element (4) is pulled out from the housing, the lower end of the rod antenna element (4) contacts the power supply fitting (7) so that both elements function as an antenna part. The upper end is a power supply fitting (7)
In the antenna device in which only the helical antenna element (2) functions as an antenna when in contact with the rod antenna element, the rod antenna element (4) and the helical antenna element (2) are formed of a continuous single metal wire,
The antenna device characterized in that the power supply fitting (7) is constituted by a leaf spring (8) that elastically holds a metal wire. 2. The antenna device according to claim 1, wherein the helical antenna element (2) is covered with a mold cap (3) which is integrally molded.